Actually, I think he had to start from lvl 1 when he re-rolled, that's why Palpatine just sent him to kill the children instead of fighting fully trained Jedi. It would also explain why he lost to Obi-Wan and why his attempted Force Charge failed so badly.

couldn't do a thing against all that expertise that Obi-Wan was stacking. bet Anakin also forgot that his previous LS III saber was rendered useless when he fell to the dark side.